Metal forming process and apparatus



April 6, 1965 G 3,176,496

METAL FORMING PROCESS AND APPARATUS Filed Dec. 11, 1962 5 Sheets-Sheet 1 F/ G. I

/06 /04 I04 10o O/ F 6 I05 b 6 J o r O o 0 J 0 Q o L //7 van for Kar/ 50m By his attorneys April 6, 1965 K. BOHM 3,176,496

METAL FORMING PROCESS AND APPARATUS Filed Dec. 11, 1962 'S SheetS-Sheet 2 //7 yen/0r Kar/ 5077/77 By his al/omeys April 6, 1965 K. BOHM METAL FORMING PROCESS AND APPARATUS 5 Sheets-Sheet 3 Filed Dec. 11, 1962 //IV6fl/0/ Kar/ 50/1/77 By his af/omeys April 6, 1965 K. BOHM 3,176,496

METAL FORMING PROCESS AND APPARATUS Filed Dec. 11, 1962 5 Sheets-Sheet 4 /n yen/0r Kar/ 56/1/77 By his affomeys April 6, 1965 K, BOHM 3,176,496

METAL FORMING PROCESS AND APPARATUS Filed Dec. 11, 1962 5 Sheets-Sheet 5 /n very/0r Kar/ 50/2/77 By his al/omeys Adam-4M.

United States Patent 3,176,496 METAL FGRBWG PRGCESS AND APPARATUS Karl Biihm, Monchen-Gladbaclr, Germany, assignor to Mannesmann-Meer, Aktiengesellschaft, Monehen-Giadbach, Germany, a German company Filed Dec. 11, 1962, Ser. No. 243,867 Claims priority, application Germany, Dec. 12, 1961, M 51,168 13 Claims. (Cl. 722-467) This invention relates to a process for straightening elongated hollow and solid bodies such as metal rods, tubes, beams, and the like, in which thematerial to be straightened is passed through a dressing tool without rotation around its longitudinal axis, and in which the dressing tool is oscillated in a plane perpendicular to the direction in which the material to be straightened is moved. The invention further relates to an apparatus for carrying out this process.

It is well known to the art that elongated bodies such as steel beams, rods, and the like, are almost always crooked or curved as they are produced, so that in most cases a subsequent straightening process is required. The straightening processes which have so far been proposed may be divided into the following classes:

(1) Processes in which a length of the material to be straightened is clamped on both ends and straightened by cold drawing. This is a spatial efiect, i.e. straightening is effected in all planes.

(2) The material to be straightened, preferably supported in two places, is moved stepwise through a mechanically or hydraulically driven straightening stamp or die, with the die acting on the material only on one side; Without rotation of the material about its longitudinal axis only straightening in one plane is possible.

(3) The material is passed continuously and without rotation about its longitudinal axis, through a system of rollers consisting of pairs of transport rollers and individual bending rollers, the axes of which are perpendicular to the direction of feed. Here too straightening takes place only in one plane.

(4) The material to be straightened is rotated about its longitudinal axis while passing through a system of hyperbolic rolls Whose axes are located obliquely to the feed direction. While spatial straightening is achieved, this system is only applicable to material having a round cr ss section.

(5) The material to be straightened is passed, by means of driving rollers, through oscillating dressing toolswithout rotation, and in this way is straightened. Two species are known: either the straightening tool oscillates in circu lar paths with varying radii, or it moves on ellipse-like paths which, however, can be varied only according to one parameter.

Aside from the first technique mentioned, cold drawing, all these operations are based on applying bending stresses. With known devices, however, the period over which bending takes place is such that the speed of the straightening operation remains behind the production time to be expected in the future. Moreover, there is a possibility that by reason of the asymmetric movement of the dressing tool, additional tensions may be applied, which after the straightening process is terminated, will remain behind as an unsatisfied tension field. As a result, an exact straightening is not assured.

3,176,496 Patented Apr. 6, 1965 file. in this connection it may he observed that generally elongated bodies are curved not simply in one plane, but spatially and such spatial curvature can be considered as the resultant of curvatures in two planes at right angles to one another.

In accordance with the invention, this objective is attained by means of a process which comprises passing the material to be straightened continuously and without rotation about its longitudinal axis through a dressing tool, causing said tool to oscillate in a plane perpendicular to the direction of movement of the material by transmitting to the tool reciprocating movements of a high frequency from each of two orthogonal directions so that the displacement in each direction is varied from zero to a maximum value independently of the other, to provide a symmetrical path for the dressing tool about the ideal central position of the material to be straightened. Such path, according to the position of the main inertial ice ' axes of the material to be straightened and the magnitude It is the purpose of the invention to provide a process v and apparatus for straightening elongated bodies which will keep pace with future production and which make possible the exact straightening of any desired cross sec- .tion or profilein that the movement of the straightening tool or tools canbe made to conform exactly to the proof the movements of resistance relative to-these axes, may.

be rectilinear, elliptical or circular or may even conform to curves of higher order.

The orthogonal movements referred to above may be of the same frequency and in phase, of the same frequency and out of phase or of differing frequencies which are, however, in integral relation to one another.

The operation referred to may be carried out at several places along the length of the material to be straightened so that the resultants' from the individual motion components are displaced with respect to one another.

It goes without saying that the material to be straightened, even when moving at a high speed, receives a sufficientlylarge number of straightening impulses.

V In its apparatus aspects the invention comprises a machine for carrying out the process described. Such machines comprise one or more dressing tools which fit around the material to be straightened, preferably vw'th free running rollers, and means for oscillating these tools at high frequencies. The tools are preferably positioned between sets of drive rolls which carry the work through the dressing tools. may comprise eccentric shafts or crank shafts. Means are preferably provided for varying the displacement or amplitudes of the oscillating movement. Thus, for example, the eccentrics may be adjustable in known manner by sleeves'with an eccentric bore. The frame of each dressing tool may be displaceably supported on two slides located perpendicular to one another.

The invention will be further described with reference to the accompanying drawing in which- FIG. 1 is a schematic view showing a general arrangement of various apparatus elements for carrying out the process of the invention.

FIG. 2 is a schematic view of a preferred type of apparatus according to the invention.

FIG. 3 is a view in front elevation and, in part, in vertical section, of a dressing tool in accordance with the invention.

FIGS. 3a, 3b and 3c are detached views of possible crankshaft arrangements in the apparatus of FIG. 3. FIGS 3a and 3b'are front views and FIG. 30 is a side view partly in vertical section.

FIG. 4 is a view in front elevation and in part-in vertical section of a dressing tool slightly modified with respect to the tool of FIG. 3.

FIG. 5 is a schematic view:of another form of apparatus according to the invention.

FIG. 6 is a schematic view of yet another form of apparatus in accordance with the invention.

FIG. 7 is aschematic drawing showing the path followed by the center of a dressing tool frame when the The means for oscillating the tools ing tools are caused to oscillate by means of reciprocating movements applied in each of two mutually perpendicular directions, for example, in the directions shown by the symbols in FIG. 1. v

The driving rolls 104 may be powered by any suitable prime mover, e.g. an electric motor, not shown. The power required to oscillate the driving tool frames 101, 182 and 193 may be furnished by any convenient source, for example, by electric motors 105, 107, 108.

Referring to FIGS. 2 and 3, the dressing tool itself may comprise a frame 1 equipped with two pairs of rolls 13 and 14 which are designed to fit over the material to be straightened, which in this case ,is shown as a wide flanged beam 1&9 having an I cross section or profile. The frame 1 is fitted to slide horizontally in a guide plate 2. The guide plate 2 is attached to a slide 3 which is pivotally suspended from a connecting rod 4 in a vertical guide'Bia by means of a pin in.

The connecting rod 4 is connected to a crankshaft 5 which is eccentrically mounted with respect to a sprocket wheel 18 in a bracket 15. The bracket is in turn positioned on a fixed standard 17. A vertical or side edge of the frame 1 is provided with a bracket in to which a connecting rod 8 is pivotally joined by a pin 8a. The rod 8 is in turn operatively connected to a sprocket wheel 19 by a crankshaft 9 eccentrically positioned with respect to the sprocket 19.

he eccentricity, i.e. the differences in centers, between the crankshaft 5 and the sprocket 18 is denoted 2 in FIG. 3. Similarly, the eccentricity of shaft 9 is denoted e Preferably the manner'in which the shafts 5 and 9 are connected to the sprockets 18 and 19 is such as to permit individual adjustment of the eccentricities e and c The particular construction used for this purpose may be any of those well known to the art. One possible construction is shown in FIG. 3A. In this construction the sprocket wheel 50 is journaled in bracket 51 by means of aboss 119. The boss 110 is drilled eccentrically to provide a sleeve 111 into which the shaft may be fixed. The eccentricity is varied by changing sprocket wheels.

A somewhat different arrangement is shown in FIGS. 3b and 3c, FIG. 30 being a view in vertical section of the structure of FIG. 3b. In these figures, a sprocket wheel 60 is journaled on bracket 15 by means of hub 61. On the outer face 62 of the sprocket is pivotally mounted sleeve 63 by means of a pin 64. It will be observed that pin 64 is positioned eccentrically with respect to the hub 61. Sleeve 63 has a socket 65, eccentrically ositioned and adapted to receive crankshaft 5. The sleeve 63 is retained in any desired position by means of retaining pin 66 which engages in any one of a series of blind holes67 in sprocket 60. To change the eccentricity e, the pin'65 is withdrawn and sleeve 63 is rotated about pin .64 to the desired position as shown in dotted lines.

It will be obvious that the same construction can be used to provide eccentricity for the crank 9.

Power may be applied to either the sprocket 18 or the sprocket 19, for example, from anielectric motor (see FIG. 1) and the other sprocket is then driven from the sprocket to which power is applied by the chain 12.

FIG. 4 shows a structure very similar to that of FIG. 3 except the bracket 115 with the crankshaft 116 and the upper bearing of the connecting rod 117 is displaced toward the right, just as the frame 118 with the rolls 113, 114 can be displaced to the right by the amount of a The connecting rod 119 is shortened (with respect to rod 8 of FIG. 3) by the same amount and the arm 12% of standard 121 is cut away so that the sliding frame does not strike it.

The operation of the apparatus of FIGS. 3 and 4 will be obvious. Referring to FIG. 3, for example, as the material to be straightened, cg. the beam 109, is moved through the tool, the shafts 5 and 9 are caused to rotate by the chain 12 and sprockets 13 and 19 driven, for in- Various arrangements of the dressing tool frame are possible, in addition to that shown in FIGS. 2 and 3. Two additional arrangements are shown schematically in FIGS. 5 and 6. In FIG. 5 the frame 1 has a top edge which travels in a horizontal sliding guide 2' which in turn is attached to a slide 3, positioned in a vertical guide 3a. The slide 3' is moved up and down in the guide 3a by crank 5' and connecting rod a. The side edge of the frame 1' moves in a vertical sliding guide 6 which is attached to a horizontally guided slide 7 which is moved back and forth in a guide 7a by crank 9' and connecting rod 8'.

FIG. 6 shows an arrangement in which the bottom edge of a dressing tool frame 1" is guided horizontally in a sliding carriage it), which in turn is displaceable in a vertical sliding guide 11. Cranks 5" and 9? are connected to the frame 1 via connecting rods 4", 8" which are pivotally attached to brackets Zll, 21 on the frame 1," thus providing for vertical and horizontal movement of the frame. a

Three of the large number of possible paths which may be followed by the dressing tool in accordance with the invention are illustrated in FIG. 7. The patterns illustrated are specifically applicable to the construction of FIG. 5. Assuming that in FIG. 5 cranks 4' and 8' are of equal length, e =e and the dressing tool moves alongthe circular path (a) of FIG. 7. If the crank 5' is made smaller than the crank 3' (e e then a horizontal ellipse results [curve (b) in FIG. 7] If crank 5' is made larger than crank 8 (e e the curve (c), a standing ellipse, results. In the limiting cases where 2 :0 and e O we get a horizontal straight line; where e 0 and e =O, a vertical straight line results.

The path followed by the tool can further be varied by driving the shafts out of phase, is. referring to FIG. 7, by having a a In sprocket wheels this is readily accomplished by a step by step shift. A stepless shift can be accomplished by eccentric sleeves. In extreme conditions the eccentric shafts can also be driven with a variable number of revolutions, for example, in the ratio 1:2, 1:3, or 1:4. The straightening tool then follows curves of a higher order. The machine is thereby transformed to a universal straightening machine useful for correcting profiles of any kind.

The invention is not limited to drives with eccentric shafts. The oscillating movements can be produced in other ways, e.g. electromagnetically, hydraulically or pneumatically.

As will appear in FIG. 1, several dressing tools may be arranged in tandem. In this case the central position of each tool is positioned to confirm to the ideal center of the work being handled. In this connection it is also possible to position drive or guide rollers before and after each dressing tool, or to omit such rollers, if each second dressing tool is left unactuated.

What is claimed is:

1. Apparatus for straightening elongated bodies comprising a dressing tool frame adapted to receive the material to be straightened, said frame having a top edge and a side edge, a horizontally sliding guide plate for receiving said top edge, a vertically guided slide, fixed to said horizontally sliding guide plate, and crank means for reciprocating said vertically guided slide in a vertical direction, in combination with a vertically sliding guide plate for receiving said side edge, a horizontally guided slide attached to said vertically sliding guide plate and crank means for reciprocating said horizontally guided slide in a horizontal direction.

2. Apparatus for straightening elongated bodies comprising a dressing tool frame having a top edge and a side edge, a horizontally sliding guide plate for receiving said top edge, a vertically guided slide fixed to said horizontally sliding guide plate, crank means for reciprocating said vertically guided slide in a vertical direction, and means comprising a crank and a connecting rod engaging said frame for reciprocating said frame in a horizontal direction in the sliding guide plate.

3. Apparatus for straightening elongated bodies which 2 comprises a dressing tool frame having a lower edge, a sliding carriage for receiving the lower edge of said frame, a vertical sliding guide, said carriage being attached to said guide, first crank means, means pivotally attaching said first crank means to the top of said frame, a second crank and means attaching said second crank to a side of said frame.

4. Apparatus for straightening elongated bodies comprising a dressing tool frame adapted to fit around the body to be straightened and means comprising crank shafts for reciprocating said frame independently in each of two orthogonal directions.

5. Apparatus as claimed in claim 4 wherein the cranks are connected to one another.

6. Apparatus as claimed in claim 4 wherein the crank radii are adjusted independently of one another.

7. Apparatus as claimed in claim 6 wherein the radii are adjustable by means of sleeves with eccentric bores.

8. The apparatus claimed in claim 4 and comprising a plurality of dressing tools arranged along a line coinciding with the center line of the shape it is desired to have the material to be straightened, assume.

9. The apparatus claimed in claim 4 and comprising driving and guiding rollers before and after each of said dressing tools, respectively.

10. A device for straightening elongated hollow and solid bodies comprising a dressing tool and means for continuously moving a body to be straightened through said tool without rotation of said body, said tool comprising two orthogonally opposed variable phase drive elements coupled with one another and each capable of transverse movement, and means for varying the amplitude of the transverse movement of each of said drive elements from zero to a maximum value, the resultant of the transverse movements of said drive elements being effectively a rotational movement of the dressing tool in a plane perpendicular to the direction of movement of the body to be straightened.

11. The device claimed in claim 10 in which the dressing tool comprises a frame adapted to fit over the body to be straightened and in which at least one of the drive elements is crank operated and engages the frame through a guide and a slide.

12. The device claimed in claim 11 wherein at least one of the drives is crank operated and directly engages said frame.

13. The device claimed in claim 10 wherein the tool comprises a frame adapted to fit over the body to be straightened and at least one of the drives is crank oper= ated and directly engages said frame.

References Cited by the Examiner UNITED STATES PATENTS 2,901,930 9/59 Wilman 153-32 3,054,43 8 9/62 Wegner et a1. 15 332 FOREIGN PATENTS 920,340 11/54 Germany.

CHARLES W. LANHAM, Primary Examiner. 

1. APPARATUS FOR STRAIGHTENING ELONGATED BODIES COMPRISING A DRESSING TOOL FRAME ADAPTED TO RECEIVE THE MATERIAL TO BE STRAIGHTENED, SAID FRAME HAVING A TOP EDGE AND A SIDE EDGE, A HORIZONTALLY SLIDING GUIDE PLATE FOR RECEIVING SAID TOP EDGE, A VERTICALLY GUIDED SLIDE, FIXED TO SAID HORIZONTALLY SLIDING GUIDE PLATE, AND CRANK MEANS FOR RECIPROCATING SAID VERTICALLY GUIDED SLIDE IN A VERTICAL DIRECTION, IN COMBINATION WITH A VERTICALLY SLIDING GUIDE PLATE FOR RECEIVING SAID SIDE EDGE, A HORIZONTALLY GUIDED SLIDE ATTACHED TO SAID VERTICALLY SLIDING GUIDE PLATE AND CRANK MEANS FOR RECIPROCATING SAID HORIZONTALLY GUIDED SLIDE IN A HORIZONTAL DIRECTION. 